JP2005138022A - Bubble generation method and bubble generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bubble generation method capable of obtaining a liquid containing fine bubbles at high density, and a bubble generator. <P>SOLUTION: In the bubble generation method, the liquid is retained so as to be contacted with a solid and a blow with a degree not destroying the solid is imparted to the solid with the bubbles present in the liquid. The bubble generator is provided with a container 1 having the liquid containing the bubbles at the inside; and a hitting means 2 for hitting a part of a wall of the container to the degree not destroying the above wall. Further, water containing a substance having a hydrophilic group and a hydrophobic group in a molecule is used as the liquid. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a bubble generation method and a bubble generation apparatus for obtaining a liquid containing bubbles, and more particularly to miniaturization of bubbles.

  In the conventional bubble generation method and bubble generation device, for example, as shown in the abstract of Patent Document 1 “Microbubble Generation Method and Device Using Ultrasonic Waves”, a microtube having a gas supply port in a liquid is used. Before the gas supplied into the liquid from the gas supply port generates complete bubbles, an ultrasonic wave is applied to the gas-liquid interface between the gas and the liquid, thereby continuously In the paragraph number [0013], the diameter of the bubble in the normal state is about 2 mm, whereas the diameter of the microbubble is 14 μm on average when ultrasonic waves are applied. In paragraph No. [0018], it is described that when the ultrasonic vibration is increased to some extent, microbubbles much smaller than the diameter of the microtube are generated.

JP 2002-113340 A

Since the conventional bubble generation device and bubble generation method are configured as described above, there is a problem that a liquid containing microbubbles at a high density cannot be obtained as will be described in detail below.
That is, the ultrasonic wave has a wavelength. For example, if it is 20 kHz, one wavelength is 7.5 cm in water. In the case of a standing wave, an antinode and a nodule portion are formed at a quarter of the wavelength of the ultrasonic wave, but bubbles are hardly miniaturized at the nodal portion, but mainly at the antinode portion. Therefore, roughly speaking, if the nodes and belly occupy half of the volume of the liquid, only half of the volume of the liquid will be used for bubble miniaturization. For example, when a 20 kHz ultrasonic wave is used, a quarter wavelength is about 1.9 cm, and a node portion is about 1 cm. That is, minute bubbles are not generated at a thickness of 1 cm. In addition, it is difficult to guide the source gas intensively to the abdomen. Therefore, it is not possible to obtain a liquid containing microbubbles at a high density.

  The present invention has been made in order to solve the above-described problems of the prior art, and provides a bubble generation method and a bubble generation apparatus capable of obtaining a liquid containing fine bubbles at high density. It is intended.

  The microbubbles referred to in the present invention are bubbles having a diameter of 100 μm or less, preferably several tens of μm or less, more preferably 10 μm or less.

  In the bubble generation method according to the present invention, the liquid is held so as to come into contact with the solid, and in the state where the bubble is present in the liquid, the solid is hit with such a degree that the solid is not destroyed.

  The bubble generating apparatus according to the present invention includes a container having therein a liquid containing bubbles and a striking means for striking a part of the container wall of the container to such an extent that the container wall is not destroyed.

  According to the bubble generation method of the present invention, the liquid is held so as to come into contact with the solid, and in the state where the bubble is present in the liquid, the solid is subjected to an impact that does not destroy the solid. It can be efficiently miniaturized and a liquid containing microbubbles at a high density can be obtained.

  According to the bubble generating device of the present invention, since it includes a container having a liquid containing bubbles therein and a striking means for striking a part of the container wall of the container to such an extent that the container wall is not destroyed, Can be efficiently miniaturized, and a liquid containing high density of microbubbles can be obtained.

Embodiment 1 FIG.
FIG. 1 is a diagram for explaining a bubble generation device and a bubble generation method according to Embodiment 1 of the present invention. More specifically, FIG. 1 schematically shows a configuration of the bubble generation device.

A bubble generation tank 1 corresponding to a container having a liquid containing bubbles inside has a rectangular parallelepiped shape, and has an inner (inner surface) width of 50 mm, a thickness of 1 mm, a length of 300 mm, and a bubble generation tank 1 corresponding to a container wall of the container. The tank wall is made of, for example, transparent acrylic and has a thickness of 5 mm. In addition, in FIG. 1, a mode that the bubble generation tank 1 was cut | disconnected by the surface parallel to the thickness direction and the length direction is shown, and the thickness of the tank wall is abbreviate | omitted.
The striking device 2 is a device capable of projecting a striking portion 2a made of, for example, vinyl chloride continuously or once with air pressure. The strength of the impact is difficult to determine, but it is only enough for a person to tap, and the wall of the bubble generation tank 1 can be deformed for a very short time by the impact, and then can be almost restored to its original shape. It is.

  A stainless steel pipe having an inner diameter of 0.5 mm is installed as a gas supply pipe 3 below the bubble generation tank 1, and a gas pump (air pump) 4 is connected to the stainless steel pipe to constitute a gas supply means. Further, a liquid supply pipe 5 different from the gas supply pipe 3 is disposed at the lower part of the bubble generation tank 1, and the liquid supply pipe 5 is connected to the mixing tank 7 via a liquid pump (water pump) 6. The liquid supply means is configured by connection. Tap water is piped into the mixing tank 7, and a bubble fusion inhibitor is dropped at an appropriate flow rate. The air pump 4 and the water pump 6 can flow gas and liquid at an arbitrary flow rate, respectively.

  In addition, FIG. 1 is a schematic diagram, and the proportional relationship of the dimensions of the bubble generation tank 1, the striking part 2a, the gas supply pipe 3, the liquid supply pipe 5, the mixing tank 7, the bubbles 8, the microbubble-containing water outlet 9 and the like is the actual size. Is different.

  As the bubble fusion inhibitor, a substance having a hydrophilic group and a hydrophobic group in one molecule, for example, acetic acid, isopropanol, hexanediol, propionic acid, isoleucine, adipic acid and the like can be used. These are certain amphiphilic organic substances that prevent the bubbles from fusing together and cannot be blown like so-called soapy water. The details of the anti-bubble fusion agent are described in Japanese Patent Application No. 2003-077113 "Bubble generator and bubble generation method" by the same applicant as the present invention. A substance having a value divided by the number of groups of 47 or more and 140 or less, (b) a substance having a carboxyl group and an amino group in the molecule and a molecular weight divided by the number of carboxyl groups of 94 or more and 280 or less, (c ) A substance having a hydroxyl group in the molecule and having a molecular weight divided by the number of hydroxyl groups of 38 to 73; (d) A substance having an ester group and having a molecular weight divided by the number of ester groups of 47 to 140 (E) A substance having a sulfonic acid group and having a molecular weight divided by the number of sulfonic acid groups of 47 or more and 140 or less.

  Such a bubble fusion inhibitor is added to water (tap water, river water, ion exchange water, pure water, etc.) so that the final concentration is about 0.001 mol / L or more and 1 mol / L or less. Mixed. When (a) a substance having a carboxyl group and a molecular weight divided by the number of carboxyl groups is 47 or more and 140 or less, the pH of the mixed solution is adjusted to 4 or less.

  As the bubble fusion inhibitor, ethanol may be used in addition to the above, and a salt such as NaCl may be added at about 1% or more if a high concentration is acceptable. In addition, substances generally referred to as surfactants, such as fatty acid esters, alkylbenzene sulfonic acids, higher alcohols, and long chain ethers, can also be used if they are not too sensitive.

  A liquid containing microbubbles (water containing microbubbles) is led out from the water outlet 9 containing microbubbles. Various effects can be obtained by connecting various application means to the tip of the microbubble-containing water outlet 9. This will be described in another embodiment.

  FIG. 2 shows a flow of a microbubble generation process according to the present embodiment. That is, the microbubble generation process according to the present embodiment is realized by the bubble fusion inhibitor mixing step 101 (realized by the mixing tank 7 in FIG. 1) and the bubble generation process 102 (the bubble generation tank 1 and the gas supply pipe in FIG. 1). 3, realized by the liquid supply pipe 5, the air pump 4 and the water pump 6) and the striking process 103 (realized by the striking device 2 in FIG. 1), and connecting the application process 104 as necessary. It is.

  Hereinafter, specific experimental examples will be described.

Experimental Example 1
As shown in FIG. 1, a rectangular cell-shaped bubble generating tank 1 has a gravity vector in which the plane (tank walls 1a and 1b) including the length direction and the width direction, that is, the plane (tank wall) orthogonal to the paper surface of FIG. It installed so that it might incline by about 10 degrees The tank wall (at least the tank wall inner surface) 1a is inclined to the side covered with the internal liquid, and the tank wall (at least the tank wall inner surface) 1b is inclined to the side for receiving the internal liquid. Tap water was used as the liquid and flowed at a flow rate of 100 mL / min. 1,2-Hexanediol was used as a bubble fusion inhibitor and dissolved and mixed in the mixing tank 7 so that the final concentration was 0.008 mol / L. Air was used as a gas and introduced at a flow rate of 1 mL / min. The bubbles 8 generated at this time were large with a diameter of about 1 mm to 2 mm. After the bubbles 8 were detached from the stainless steel tube 3, they rose in water, then hit the tank wall 1 a and further increased along the tank wall 1 a. Thereafter, the water was led out from the water outlet 9 containing fine bubbles together with water.

  Next, in the same manner, while supplying water and air containing the bubble fusion inhibitor to the bubble generation tank 1, at the same time, the striking device 2 contacts the tank wall 1a of the bubble generation tank 1 with the liquid on the tank wall 1a. Strokes were given once per second from the opposite side. Then, the bubbles 8 that had been rising were refined (miniaturized), and the water became cloudy. A photograph taken with a CCD camera from the direction of the tank wall 1b is shown in FIG. 3 together with a 10 mm scale. In FIG. 3, the bubbles that appear black are bubbles that appear white in water without bubbles. As can be seen, the bubbles 8 that were 1 mm or more before being blown were instantly miniaturized, and the water became cloudy due to the microbubbles.

  Furthermore, the moment of hitting was shot from the direction of the tank wall 1b with an ultra-high speed video camera. The results are shown in FIGS. 4A to 4D together with a 1 mm scale. The batting was done only once. The photograph shown in FIG. 4 is a continuous image taken every approximately 1 millisecond. (A) is before hitting, and bubbles with a diameter of about 1 mm are shown. (A) is immediately after the blow, and the round bubbles are greatly deformed. (C) and (d) are scenes where minute bubbles are generated. Although it was difficult to understand the size of bubbles from this photograph alone, it was found that many bubbles of about 10 μm were included. Moreover, when the impact was continuously performed, all the bubbles that did not become 10 μm or less at one time also became 10 μm or less. Water containing only microbubbles of 10 μm or less appeared completely cloudy, and the cloudy water was sent out from the water outlet 9 containing microbubbles.

  In the above experimental example, since the tank wall (at least the tank wall inner surface) 1a of the bubble generating tank 1 is tilted by 10 ° to the side covering the liquid inside, the original bubbles to be micronized easily come into contact with the inner wall of the vessel wall. Although finer bubbles could be obtained, the tank wall (at least the tank wall inner surface) 1a of the bubble generation tank 1 does not necessarily have to be inclined. Further, even when tilted, the angle is not limited to 10 ° and may be less than 90 °. Furthermore, 90 degree, ie, the tank wall (at least tank wall inner surface) 1a may be in a state of lying down. Further, when tilted over 90 °, bubbles are difficult to be produced because the microbubble-containing water outlet 9 that is the outlet of the bubbles is lower than the gas supply pipe 3 installation position of the bubble generation tank 1 that is the inlet. There are bubbles, but the bubbles are miniaturized.

  Moreover, in the above experimental example, hexanediol was used as an additive (bubble fusion inhibitor), but the present invention is not limited to this, and the value obtained by dividing the molecular weight by the number of carboxyl groups (a) having a carboxyl group as described above. A substance having a molecular weight of 47 to 140, (b) a substance having a carboxyl group and an amino group in the molecule and a molecular weight divided by the number of carboxyl groups being 94 to 280, and (c) a molecular weight having a hydroxyl group in the molecule. (D) a substance having an ester group and a molecular weight divided by the number of ester groups of 47 to 140, and (e) a sulfonic acid group. Any substance whose molecular weight divided by the number of sulfonic acid groups is 47 or more and 140 or less may be added. Specifically, for example, acetic acid, isopropanol, propionic acid, isoleucine, adipic acid and the like may be used. Further, ethanol may be used. Further, if a high concentration is acceptable, a salt such as NaCl may be added by about 1% or more. Other surfactants can be used if you don't mind blowing.

  In addition, the number of hits is 1 time / second in Experimental Example 1 described above, but the number of hits is not limited to this. However, the larger the number, the smaller the bubbles tend to be.

  Moreover, although the water flow rate was also 100 mL / min, it is not restricted to this, and it may be more or less.

  Moreover, although the gas flow rate was 1 mL / min, this depends on the water flow rate, and if it is less than this, the bubble diameter tends to be small. On the other hand, when the amount is too large, bubbles are not formed, and it is desirable that the water flow rate is about 1/10 or less. However, this also depends on the shape and size of the bubble generating tank 1 and the area of the hitting portion 2a. In general, the larger the bubble generation tank 1 and the larger the area of the hitting portion 2a, the greater the air flow rate.

  Moreover, although air was used as the gas, oxygen, ozone, carbon dioxide, methane, chlorine, etc. may be used. However, when the solubility of carbon dioxide gas or ammonia in water is very high, it is necessary to increase the bubble flow rate compared to other types.

Experimental example 2.
The striking device 2 may be installed not only on one surface of the bubble generation tank 1 but also on a plurality of surfaces, and may be struck simultaneously from a plurality of surfaces of the bubble generation tank 1. As an example, the bubble generation tank 1 has a rectangular parallelepiped shape, the inner surface has a width of 20 mm, a thickness of 20 mm, a length of 100 mm, and the tank wall is made of, for example, transparent acrylic and has a thickness of 5 mm. The bubble generation tank 1 is installed so that the plane including the length direction and the width direction (tank walls 1a and 1b), that is, the plane orthogonal to the paper surface of FIG. did. The striking device 2 was installed on each of four surfaces (four tank walls) parallel to the length direction of the bubble generating tank 1, and the four tank walls were simultaneously hit from the surface opposite to the liquid contact surface.
As a result, the microbubbles became smaller. Moreover, the bubble diameter became uniform compared with the case where the striking device 2 of Experimental Example 1 was one. This is considered to be because the impact energy on the introduced bubbles becomes uniform by increasing the number of impact devices 2.

  In the above description, the striking device 2 that uses fluctuations in air pressure has been described. However, any device that provides striking force may be used. For example, a weight is attached to the tip of a spring, and the force that the spring extends is used. For example, the weight is applied to the bubble generation tank 1 and the weight is rotated to apply the weight to the bubble generation tank 1.

  The cross-sectional shape perpendicular to the length direction of the bubble generating tank 1 does not have to be a square, and may be anything such as a triangle, hexagon, octagon, circle, or ellipse. If it is made hexagonal or circular, the striking device 2 or the striking site can be increased, and smaller microbubbles can be obtained.

  As described above, according to the present embodiment, the liquid is held so as to be in contact with the solid (bubble generating tank 1), and the solid is blown to the extent that the solid is not destroyed in the state where the bubbles are present in the liquid. Air bubbles are miniaturized by giving to. Specifically, the container (bubble generating tank 1) having a liquid containing bubbles inside and a part of the container wall (tank wall of the bubble generating tank 1) of the container so as not to destroy the container wall (tank wall). And a striking means 2 for striking. Therefore, the conventional technology that generates microbubbles by applying ultrasonic waves to the gas-liquid interface between the gas and the liquid described above is less efficient because it can be miniaturized only in the abdominal part of the standing wave. In the present embodiment, by shortening the distance between the tank walls 1a and 1b, the bubbles can be miniaturized in the entire area between the tank walls 1a and 1b. Thus, the bubbles can be efficiently miniaturized, and a liquid containing the microbubbles at a high density can be obtained.

Embodiment 2. FIG.
In the first embodiment, the bubble generation tank 1 has a gravity vector whose plane (at least the inner surfaces of the tank walls 1a and 1b) including the length direction and the width direction, that is, a plane (tank wall) orthogonal to the paper surface of FIG. It was installed so as to be inclined, and the upper tank wall 1a (tank wall 1a inclined to the side covered with the liquid inside) of the tank walls 1a and 1b including the length direction and the width direction was hit. The lower tank wall 1b (the tank wall 1b inclined to the side for receiving the liquid inside) may be hit as shown in FIG.

  In this case, since the energy of impact is transmitted to the bubbles 8 through water, the thinner the water, that is, the shorter the distance between the upper tank wall 1a and the lower tank wall 1b, Bubbles become smaller. Moreover, in that case, although depending on the structure and material of the hitting portion 2a and the tank wall, the larger the position of the bubble is from the tank wall 1b on the hit side, the larger the generated bubble. As a result, a distribution occurs in the bubble diameter exiting from the bubble generation tank 1.

  That is, when it is desired to obtain bubbles having a uniform size, the tank wall 1a on the upper side of the inclined bubble generation tank 1, that is, the side where the bubbles 8 that are introduced from the stainless steel tube 3 are easily contacted is hit. However, if it is desired to obtain bubbles of various sizes at the same time, it is better to strike the lower tank wall 1b.

In order to obtain such bubble size distribution, the plane including the length direction and the width direction of the bubble generation tank 1 (at least the inner surfaces of the tank walls 1a and 1b) is parallel to the gravity vector. The bubbles installed and introduced into the bubble generation tank 1 may be distributed as evenly as possible in the bubble generation tank 1. In this case, if one of the tank walls 1a and 1b is hit, the distribution width of the bubble size increases, and if both the tank walls 1a and 1b are hit, the distribution width of the bubble size is narrow. The ratio of micronized bubbles increases.
The case where it is desirable to obtain bubbles of various sizes at the same time includes, for example, the case where water containing fine bubbles is used for degreasing, and this will be described later.

Embodiment 3 FIG.
In each of the above-described embodiments, the gas supply pipe 3 and the gas pump 4 are used to introduce the bubbles into the bubble generation tank 1, but a device generally called a microbubbler or a microbubble generator may be used. The main devices of this type are those that release gas from a collection of microscopic holes, such as glass powder sintered bodies called glass filters, similar ceramic or metal sintered bodies, and bundles of thin tubes. Or a metal plate or plastic film having a plurality of minute holes. As another method, there is a method in which intense turbulence is caused and gas is drawn into the device, for example, an ejector, a dynamic mixer, or an impeller agitation. Further, there is a type in which a gas is once dissolved in a liquid at high pressure or low temperature, and then the gas is changed to low pressure or high temperature to make the gas bubbles. Furthermore, there is a combination of any of the above.

  Hereinafter, an embodiment for generating water containing fine bubbles using an ejector will be described with reference to FIG. The ejector 10 uses a phenomenon in which a constricted portion is formed in a pipe, and when high-pressure water is introduced from one side, the constricted portion becomes a low pressure, and a gas inlet is provided in the low-pressure portion (constricted portion). When the gas supply pipe 3 is connected, the gas is caught in the liquid. Since the entrained portion becomes a violent turbulent flow, the gas is torn off and relatively small bubbles are generated. The so-called aspirator also uses this principle. When an ejector is used, there is a merit that only a water pump 6 is required as a power source, that is, a gas pump is unnecessary.

Hereinafter, specific experimental examples will be described. When the water flow rate was 10 L / min, air was sucked in at 6 L / min. Since both the amount of water and the amount of air are much larger than those in the experimental example shown in the first embodiment, it is necessary to enlarge the bubble generating tank 1 and the striking portion 2a. Therefore, the inner side (inner surface) of the bubble generation tank 1 has a width of 50 mm, a thickness of 10 mm, and a length of 1000 mm, and the tank wall is made of, for example, transparent acrylic and has a thickness of 10 mm. The striking force was increased to about 10 times that of the first embodiment. The striking area was also increased about 10 times, and the striking frequency was also about 10 times / second. Other conditions were the same as those in Experimental Example 1 of the first embodiment.
As a result, the diameter of the bubbles 8 immediately after being introduced from the ejector 10 was mostly about 0.5 mm, but most of the bubbles emerging from the microbubble-containing water outlet 9 were about 30 μm, but 10 μm Many of the following were also included:

  FIG. 6 is a schematic diagram, and the proportional relationship of dimensions of the bubble generation tank 1, the striking part 2a, the gas supply pipe 3, the liquid supply pipe 5, the mixing tank 7, the bubbles 8, the microbubble-containing water outlet 9, the ejector 10, and the like. Is different from the actual size.

  For example, as in Experimental example 2 of the first embodiment, the impact device 2 is installed on each of four surfaces (four tank walls) parallel to the length direction of the bubble generating tank 1, or as in the second embodiment. In addition, when the striking frequency is changed or the water flow rate is changed, for example, the lower tank wall 1b (tank wall 1b inclined to catch the liquid inside) is hit, the distribution of the diameter of the bubbles that come out changed. This is the same as described in the first and second embodiments.

  In the case of the present embodiment, the bubble generation step 102 shown in the flow chart of the microbubble generation process in FIG. 2 is replaced with a gas-liquid mixing step.

Embodiment 4 FIG.
FIG. 7 is a diagram for explaining a bubble generation device and a bubble generation method according to Embodiment 4 of the present invention. More specifically, FIG. 7 schematically shows a configuration of a main part of the bubble generation device.
In each of the above-described embodiments, the tank wall inner surface of the bubble generation tank 1 (the inner wall surface of the container having a liquid containing bubbles) is not subjected to any processing and remains a flat transparent acrylic. In contrast, in the present embodiment, at least a part of the inner surface of the tank wall that comes into contact with the liquid in the bubble generating tank 1 is made hydrophobic. In FIG. 7, 11 is a tank wall whose inner surface is hydrophobic.

  As described above, since at least a part of the inside of the bubble generation tank 1 is made hydrophobic, the introduced bubbles and the micronized bubbles are likely to adhere to the hydrophobic portion. Becomes longer. Further, when the bubbles adhere to the tank wall, more impact energy can be received. As a result, finer bubbles can be obtained compared to the case where the hydrophobicity is not used. In particular, when the amount of introduced bubbles was small, a remarkable effect was obtained.

  To make the inner surface of the tank hydrophobic, the tank wall is made of a hydrophobic material such as fluororesin or polyethylene, the inner surface of the tank wall is covered, or a hydrophobic substance such as grease is applied to the inner surface of the tank wall. This can be achieved by chemical adsorption or physical adsorption of an adsorbent having a hydrophobic group on the inner surface of the glass or metal that constitutes the material, for example, a silane agent or a substance having a thiol group such as alkylthiol. .

Although the inner surface of the bubble generating tank 1 may be made entirely hydrophobic, it is effective even when only a part is made hydrophobic.
For example, as shown in FIG. 7, a rectangular parallelepiped bubble generating tank 1 is provided with planes (tank walls 1a, 1b) including the length direction and the width direction, that is, planes (tank walls) orthogonal to the paper surface of FIG. Is installed so as to be inclined with respect to the gravity vector, the inner surface of the tank wall 1a which is inclined to the side covered with the liquid inside is liable to be attached to the introduced bubbles or micronized bubbles. By making hydrophobic, it becomes easier for the bubbles to adhere. Therefore, it is preferable that the bubbles can be efficiently refined by hitting this portion.
In addition, the hydrophilicity in the vicinity of the outlet of the bubble generating tank 1 has an effect of smoothly generating the generated bubbles.
Further, even if the entire inner surface of the bubble generating tank 1 or the entire inner surface of the tank wall 1a inclined toward the liquid-covered side in FIG. There was an effect to.

Embodiment 5 FIG.
In the fourth embodiment, the case where at least a part of the inner surface of the tank wall in contact with the liquid is hydrophobic is shown, but the same effect can be obtained when at least a part of the inner surface of the tank wall in contact with the liquid has irregularities. Is obtained.
As specific examples of the unevenness, FIG. 8 shows a case where the protrusion 12 is provided, FIG. 9 shows a case where the groove 13 is provided, and FIG. 10 shows a case where the stepped protrusion 14 is provided. The groove 13 in FIG. 9 and the stepped protrusion 14 in FIG. 10 were formed by rubbing the tank wall with a file or a paper file. Further, the protrusion 12 in FIG. 8 was formed by adhering a large number of cylindrical micropolystyrenes having a diameter of 0.1 mm and a length of 0.5 mm to the tank.

  All of these irregularities are those to which the introduced bubbles are likely to adhere, and were sufficiently effective in miniaturizing the bubbles in the same manner as the tank wall in which the inner surface described in the fourth embodiment was made hydrophobic. In particular, when the stepped protrusion 14 is provided as shown in FIG. 10, the impact energy is concentrated in the groove between the adjacent stepped protrusions 14, or compared to the case shown in FIGS. 8 and 9. The generated bubbles became smaller.

  In addition, although you may make it have an unevenness | corrugation in all the insides of the bubble generation tank 1, it was effective also when it was made to have an unevenness | corrugation only in a part like the case of the said Embodiment 4. FIG.

Embodiment 6 FIG.
FIG. 11 is a diagram for explaining a bubble generation device and a bubble generation method according to Embodiment 6 of the present invention. More specifically, FIG. 11 schematically shows a configuration of a main part of the bubble generation device. FIG. 11A is a transverse sectional view, and FIG. 11B is a longitudinal sectional view.
In each of the above embodiments, the case where the bubble generation tank 1 (container having a liquid containing bubbles) has a rectangular parallelepiped shape has been mainly described. However, in the present embodiment, the bubble generation tank 1 has a double cylindrical shape. Have. A liquid containing bubbles (bubble-containing water) flows between the outer cylinder (outer cylindrical tank wall) 110 and the inner cylinder (inner cylindrical tank wall) 120. Further, the impact device 2 is disposed further inside the inner cylinder 120. As the striking device 2, for example, a compressed air drive type is used, and it has a compressed air flow passage 2b.

  With such a configuration, it was possible to easily give impact energy to the entire bubble-containing water flowing between the inner and outer cylinders 1a and 1b. As a result, a large number of microbubbles could be easily obtained.

  In FIG. 11, the liquid (bubble-containing water) flows between the outer cylinder (outer cylindrical tank wall) 110 and the inner cylinder (inner cylindrical tank wall) 120, and the impact device 2 is further connected to the inner cylinder 120. The inner cylinder 120 (inner cylindrical tank wall) is arranged to hit the inner cylinder, and as shown in FIG. The impact device 2 is disposed between the outer cylinder (outer cylindrical tank wall) 110 and the inner cylinder (inner cylindrical tank wall) 120, and the inner cylinder 120 (inner cylindrical tank wall) is disposed. You may comprise so that it may hit, and the same effect is acquired.

Embodiment 7 FIG.
FIG. 13 is a diagram for explaining a bubble generation device and a bubble generation method according to Embodiment 7 of the present invention. More specifically, FIG. 13 is a diagram schematically showing a configuration of a main part of the bubble generation device.
In the present embodiment, for example, a compressed air driven striking device 2 as shown in FIG. 13 is inserted into a hermetically sealed metal box 21 or the like, and the box 21 is a liquid containing bubbles (containing bubbles). Water) was inserted into the bubble generation tank 1 (bubble-containing water) flowing in from the bottom.
Many fine bubbles were obtained by hitting the wall of the box 21 from the inside. The bubble-containing water is supplied into the bubble generation tank 1 through the bubble-containing water supply pipe 20.
Further, the box 21 in which the striking device 2 is inserted is held at a predetermined position of the bubble generating tank 1 by, for example, a support 22 fixed to the bubble generating tank 1.

  In the present embodiment, the bubble generation tank 1 and the box 21 constitute a container having a liquid containing bubbles therein, and the wall of the box 21 corresponds to the container wall of the container.

  As described above, according to the present embodiment, microbubbles are generated very simply by inserting the box 21 in which the striking device 2 is inserted into the bubble generating tank 1 holding the bubble-containing water. There is an effect that can be made.

  Of course, even if a liquid enters the box 21, bubbles are miniaturized due to the impact, so it is not an absolute requirement that the box 21 be confidential. However, the liquid inside the box 21 may weaken the striking force and may damage the striking device 2. Further, if a part of the box 21 is put out from the water surface, the box 21 does not necessarily need to be airtight, and the part of the box 21 protruding from the water surface may be opened.

  As shown in FIG. 14, the batting device 2 is inserted by integrating the box 21 in which the batting device 2 is inserted with a bubble supply device 24 made of, for example, a glass filter with a small hole. The box 21 and the bubble supply device 24 can be inserted into the bubble-containing water at a time, and microbubbles can be generated more easily.

Embodiment 8 FIG.
FIG. 15 is a view for explaining a bubble generation device and a bubble generation method according to Embodiment 8 of the present invention. More specifically, FIG. 15 is a longitudinal sectional view schematically showing a configuration of a main part of the bubble generation device. is there.
In the said Embodiment 1-6, the bubble was introduce | transduced from the liquid inlet of the bubble generation tank 1, or its vicinity. On the other hand, in the present embodiment, the tank wall 1a corresponding to the instrument wall portion struck by the striking device 2 (for example, as shown in FIG. When the plane including the direction and the width direction is installed so as to be inclined with respect to the gravity vector, a plurality of holes 25 are provided in the tank wall 1a) inclined to the side covering the liquid inside and supplied from the gas supply path 26. A gas (for example, air) is discharged as a bubble from the hole 25 into a liquid (for example, water) inside the bubble generation tank 1.

  By adopting such a configuration, it was possible to more efficiently attach bubbles to the tank wall 1a, which is a vessel wall hit by the hitting device 2, and to obtain a larger number of finer bubbles.

  As shown in FIG. 15, it may be configured to strike the tank wall 1 a that discharges bubbles, or as opposed to the tank wall 1 a that discharges bubbles as shown in FIG. 16. You may comprise so that the tank wall 1b arrange | positioned may be hit. In addition, as a method of forming the tank wall 1a having a plurality of holes 25, holes may be formed in a solid such as metal, plastic or glass with a drill or a laser beam, or glass particles, metal particles or ceramic particles are solidified. Alternatively, a solid in which small holes are formed may be used for the tank wall 1a. It is desirable that the tank wall 1a is hard, but bubbles were miniaturized even in a soft sheet.

Embodiment 9 FIG.
FIG. 17 is a diagram for explaining a bubble generation device and a bubble generation method according to Embodiment 9 of the present invention. More specifically, FIG. 17 is a longitudinal sectional view schematically showing a configuration of a main part of the bubble generation device. is there.
In the said Embodiment 1-5, the tank wall 1a was inclined so that the bubble supplied might become easy to contact the tank wall 1a. On the other hand, in the present embodiment, in order to make the bubbles come into contact with the tank wall 1a more efficiently, the liquid containing the bubbles is jetted to hit the tank wall.

  More specifically, as shown in FIG. 17, for example, a jet of water containing bubbles is generated in the ejector 10, and when this is struck against the tank wall 1 a where the impact device 2 is installed, it is shown in FIG. 6. As compared with the case where the bubbles were supplied from the bottom surface of the bubble generation tank 1, smaller bubbles were generated.

  In the above description, the ejector 10 is used to generate the jet of bubble-containing water, but it is needless to say that the present invention is not limited to this.

Embodiment 10 FIG.
In order to obtain finer bubbles in the miniaturization of bubbles by hitting the vessel wall, it is preferable that the supplied bubbles are smaller.
Therefore, as a result of intensive studies by the inventors of the present invention, a bubble supply device that has obtained the smallest bubbles so far will be described.
In the third embodiment, as an example of a device called a microbubbler or a microbubble generator, a device that discharges gas from a collection of micropores such as a glass filter can be used. When a gas is discharged to generate bubbles, bubbles having a diameter larger than the hole diameter are generated. The released bubbles first create a dome around the hole, which swells like a balloon and finally rises. This balloon-like bubble is referred to as a balloon bubble here. If the liquid or the hole is stationary, the balloon bubble rises as a bubble in the liquid when the bonding force with the hole is smaller than the buoyancy.

According to our experiments, it was found that the bonding force depends on the material and shape around the hole and the properties of the liquid. That is, as a condition for forming smaller bubbles, when water is used as the liquid, the material around the hole is preferably a hydrophilic material rather than a hydrophobic material having a weak affinity for water. That is, glass or metal is better than fluororesin or polypropylene. Of course, plastics that have been hydrophilized are also acceptable. The smaller the hole size, the better.
For liquids, the smaller the surface tension, the better, but not much affected. However, it is the relative movement of the pores and the liquid that has a greater effect than these. That is, when the combined force of force and buoyancy due to these movements exceeds the bonding force between the gas and the periphery of the hole, the gas is released into the liquid as bubbles. Since buoyancy basically increases as bubbles increase, in order to become bubbles only with buoyancy, it is necessary that the bubbles be larger than the hole diameter. However, when other forces are applied, smaller bubbles are generated. It occurs.

  As a specific example of the bubble supply device, as shown in a longitudinal sectional view in FIG. 18, a cylindrical glass filter having a 2 mm outer diameter smaller than the inner diameter of the circular tube 27 (push small glass particles by heat). 28) is inserted, and a water channel of about 1 mm is formed around the glass filter 28 (between the circular tube 27 and the glass filter 28), and water is allowed to flow at a linear flow rate of 5 m / sec. On the other hand, air was supplied at 0.5 L / min through the glass filter 28 into the water stream. Note that end plates 29 made of, for example, silicone rubber were disposed at both ends of the cylindrical glass filter 28 in order to prevent gas from leaking.

When this bubble supply device was installed in a water tank, many bubbles with a diameter of about 20 μm to 100 μm were obtained. The water in the water tank contained hexanediol at 0.008 mol / L.
Then, when this bubble supply apparatus was installed instead of the ejector 10 of FIG. 17 and the tank wall 1a was struck, many micro bubbles having a diameter of 5 μm to 20 μm were obtained. A photograph of the state of the bubbles at this time taken with a CCD camera from the direction of the tank wall 1b is shown in FIG. 19 together with a 2 mm scale. Bubbles appear black.

  In the above description, the member that discharges the bubbles is the glass filter 28, but a stainless plate or plastic plate with a minute hole or a thin tube can also be used. What is necessary is that the water flow exists in a direction substantially perpendicular to the direction in which the bubbles are released, and the faster the water flow, the smaller the bubbles.

As another configuration of the bubble supply device using the water flow, FIG. 20 shows a case where a microhole (gas discharge hole) 30 for gas discharge is opened in a box 31 made of a stainless steel plate and the gas supply pipe 3 is connected. A longitudinal sectional view is shown. There are three boxes 31, which are fixed by a fixing member 32 so that the surfaces on which a large number of gas discharge holes 30 having a diameter of about 100 μm are provided face each other with a predetermined gap (for example, about 1 mm) for water flow passage. The water flow passed through a gap having a width of about 1 mm at a linear flow velocity of 5 m / sec as in the case of FIG. Thereby, although it was large compared with the case where the glass filter 28 of FIG. 18 was used, many micro bubbles with a diameter of 50 μm to 200 μm were obtained.
Moreover, when this bubble supply apparatus was installed instead of the ejector 10 of FIG. 17 and the tank wall 1a was struck, many micro bubbles having a diameter of 5 μm to 20 μm were obtained.

  Note that the bubble supply device using a water flow as shown in FIGS. 18 and 20 does not necessarily need to be combined with a device for micronizing bubbles by hitting the tank wall, and may be used as a microbubble generator as it is. it can.

Embodiment 11 FIG.
So far, the bubble miniaturization has been described, but in the following, the microbubbles thus obtained (obtained without hitting the tank wall with the bubble supply device using the water flow described in the tenth embodiment). (Including the generated bubbles) will be described.
First, there is a degreasing apparatus. It has been already described in Japanese Patent Application No. 2003-077113 filed by the same applicant as that of the present invention that the bubbles have a strong affinity with the oil and can be washed by a bubble water flow. By the way, there are fine scratches on the object to be cleaned, and if there is oil in it, it is difficult for bubbles to reach there and to be washed. However, when the liquid containing microbubbles (water containing microbubbles) generated by the bubble generating method or the bubble generating apparatus according to the present invention is made to strike the surface to be cleaned, the oil in such scratches can also be removed. did it. Oils include petroleums, lubricating oils, machine oils and edible fats and oils. For example, it can be used as a dishwasher.

  The amount of gas dissolved in a liquid generally depends on the pressure of the gas, but the time required to reach an equilibrium state between the pressure of the gas and the concentration in the liquid depends on the interface area between the gas and the liquid. The larger the interfacial area, the faster and more convenient it is to melt. If the total gas volume is the same, the interface area increases as the bubble diameter decreases. Therefore, if the gas is made into microbubbles using the bubble generator of the present invention, the dissolution rate can be significantly increased. Furthermore, when a pressure of 1 atm or higher is applied to water containing fine bubbles and dissolved, the supersaturated state is maintained even when the pressure is returned to 1 atm, and bubbles are not generated. This is because, in general, in order to generate bubbles from a supersaturated state, fine particles called bubble nuclei are required.

That is, by using the bubble generating device according to the present invention, gaseous supersaturated dissolved water can be easily obtained. For example, when ozone is used as the gas, if it is used as ultra-high-concentration ozone water for removing organic substances, it can be an unprecedented efficient organic substance cleaning apparatus. This is because the organic removal rate generally depends on the ozone concentration. For the same reason, it can also be used for generating a high-speed silicon oxide film.
Furthermore, if methane is used as the gas and it is microbubbled to a low temperature, it can be hydrated relatively easily and used for transport and storage of methane.

  Further, if the bubbles are microbubbles, the ascending speed is very small, so that it can be regarded as water in which gas is dissolved at a substantially high concentration. When oxygen or air is used as the gas, it is also a method for improving the environment of aquatic organisms. Therefore, it can be used effectively for aquaculture of aquatic organisms and removal of anaerobic organisms.

  It is also effective as a bubble bath. In this case, it is desirable to use a biologically-derived substance or a substance approved as a food or food additive or medicine, such as an amino acid such as acetic acid, ethanol or leucine, sodium chloride, as the anti-bubble fusion agent.

  It has been explained that the bubble generating device described so far is used to generate minute bubbles. However, if the impact energy is made lighter, the gas-liquid interface of the bubbles that are the basis of the microbubbles vibrates violently even if the microbubbles are not generated. As a result, the gas in the bubbles dissolves in the liquid more quickly, for example, by increasing the area of the gas-liquid interface or accelerating diffusion. Therefore, in all the bubble generating devices described so far, in addition to the method of generating microbubbles, it is possible to use the method of dissolving the gas without necessarily going through the process of generating microbubbles.

  In all of the above-described embodiments, the addition of the bubble fusion inhibitor can prevent the bubbles from fusing, so that an effect that a larger number of microbubbles can be obtained is recognized, but it is not necessarily added. . When not added, the generated bubble diameter becomes large, but the bubble is made smaller by the bubble generation method or the bubble generation device according to the present invention as compared with the original bubble.

It is a figure which shows typically the structure of the bubble generator by Embodiment 1 of this invention. It is a figure which shows the flow of the microbubble generation process by Embodiment 1 of this invention. It is a figure which concerns on Embodiment 1 of this invention and shows the photograph which image | photographed the mode of the bubble after hitting with the CCD camera. It is a figure which concerns on Embodiment 1 of this invention and shows the photograph which image | photographed the mode of the bubble at the moment of impact with the ultra high-speed video camera. It is a figure which shows typically the principal part structure of the bubble generator by Embodiment 2 of this invention. It is a figure which shows typically the structure of the bubble generator by Embodiment 3 of this invention. It is a figure which shows typically the structure of the principal part of the bubble generator by Embodiment 4 of this invention. It is a figure which shows typically the structure of the principal part of the bubble generator by Embodiment 5 of this invention. It is a figure which shows typically another structure of the principal part of the bubble generator by Embodiment 5 of this invention. It is a figure which shows typically another structure of the principal part of the bubble generator by Embodiment 5 of this invention. It is a figure which shows typically the structure of the principal part of the bubble generator by Embodiment 6 of this invention. It is a figure which shows typically another structure of the principal part of the bubble generator by Embodiment 6 of this invention. It is a figure which shows typically the structure of the bubble generator by Embodiment 7 of this invention. It is a figure which shows typically another structure of the bubble generator by Embodiment 7 of this invention. It is a figure which shows typically the structure of the principal part of the bubble generator by Embodiment 8 of this invention. It is a figure which shows typically another structure of the principal part of the bubble generator by Embodiment 8 of this invention. It is a figure which shows typically the structure of the principal part of the bubble generator by Embodiment 9 of this invention. It is a longitudinal cross-sectional view which shows typically the structure of the principal part of the bubble generator by Embodiment 10 of this invention. It is a figure which concerns on Embodiment 10 of this invention and shows the photograph which image | photographed the mode of the bubble after hit | damaging with the CCD camera. It is a longitudinal cross-sectional view which shows typically another structure of the principal part of the bubble generator by Embodiment 10 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Bubble generation tank, 1a, 1b Tank wall, 2 Stroke device, 2a Stroke part, 2b Compressed air flow path, 3 Gas supply pipe, 4 Gas pump, 5 Liquid supply pipe, 6 Liquid pump, 7 Mixing tank, 8 Bubble, 9 Water outlet containing fine bubbles, 10 Ejector, 11 Tank wall with hydrophobic inner surface, 12 protrusions, 13 grooves, 14 stepped protrusions, 20 bubble-containing liquid supply pipe, 21 box, 22 support, 24 bubble supply device , 25 holes, 26 gas supply path, 28 glass filter, 30 gas discharge hole, 31 box, 32 fixing member, 110 outer cylinder (outer cylindrical tank wall), 120 inner cylinder (inner cylindrical tank wall).

Claims (8)

A method of generating bubbles, characterized in that the liquid is held so as to come into contact with the solid, and the solid is blown to the extent that the solid is not destroyed in a state where bubbles are present in the liquid. 2. The bubble generation method according to claim 1, wherein water containing a substance having a hydrophilic group and a hydrophobic group in one molecule is used as the liquid. A bubble generating apparatus comprising: a container having a liquid containing bubbles therein; and striking means for striking a part of the container wall of the container to such an extent that the container wall is not destroyed. 4. The bubble generating device according to claim 3, wherein the container includes a vessel wall inner surface inclined at 5 ° or more and 90 ° or less on a side covering the liquid with respect to the gravity vector. 4. The bubble generating device according to claim 3, wherein at least a part of the inner surface of the vessel wall in contact with the liquid is hydrophobic. 4. The bubble generating device according to claim 3, wherein at least part of the inner surface of the vessel wall that contacts the liquid has irregularities. 4. The microbubble generator according to claim 3, wherein a hole for discharging a gas into the liquid inside the container is provided in the wall of the container hit by the hitting means. 8. The microbubble generator according to claim 3, wherein water containing a substance having a hydrophilic group and a hydrophobic group in one molecule is used as the liquid.